The difference between RTU and PLC?

What is the difference between RTU and PLC?

The difference between RTU and PLC

What is RTU?

RTU is a remote terminal equipment, which is an automatic equipment based on "telecontrol" technology (telemetry, remote signaling, remote adjustment, remote control) installed in power plants and substations in the power grid dispatching automation system. It has the functions of remote control reception, output execution, telemetry, and data collection and transmission of remote signaling. With the rapid development of technology, it has been widely used in various industrial fields.

The most notable feature of RTU is the remote function, that is, the monitoring function completed by the long-distance information transmission between it and the dispatch center.

PLC

What is PLC?

PLC is a programmable logic controller, which performs data aggregation and instruction processing in the field station. It has a variety of control functions, data acquisition, storage and processing functions, mathematical operation functions, input/output interface conditioning functions, communication networking functions, man-machine interface functions, editing and debugging functions.

1. RTUs are generally not restricted by geographical environment and can be installed near outdoor on-site measurement points. One RTU can control several, dozens or hundreds of I/O measurement points on site, so it has a strong ability to adapt to harsh environments. Its working temperature is generally -40~85 ℃; the protection level is high, and it can be used for submarine work; the working time of a battery pack is sometimes as long as several months. PLC is generally mainly used for the control of the industrial assembly line in the plant, and it is installed indoors. The working environment temperature should be 0--55℃, and the air humidity should be less than 85%. If the temperature exceeds 55°C, install a fan for ventilation, and if the temperature exceeds 60°C, install a fan or air cooler to cool down.

2. Since the RTU is not constrained by the working environment, its technical specifications are required to meet the harsh environment requirements and specific requirements. It has a large amount of data storage, strong analog acquisition capability (up to 24 channels), and its analog function is far more powerful than PLC.

3. RTU communication function is powerful. Because the RTU will finally transmit the collected analog quantity, switch quantity, and digital quantity information to the dispatching center, and the dispatching center is sometimes thousands of miles away, it is required to have the function of long-distance communication. Although PLC also has communication function, it is only limited to transmit data within a short distance within the factory station, and its communication function is slightly inferior to that of RTU.

4. Traditional RTUs do not have programmable operation functions. Most of the current RTUs have programmable operation functions, as well as PID control functions or logic control functions, and flow accumulation functions. Since it is an emerging technology, it is bound to be a more advanced technology. It has ladder diagram and C language programming, screen configuration software programming and other technologies, strong computing ability, and can bring liquid crystal display, local display and control. All of these are incomparable to PLC.

5. The functions of RTU and PLC are not the same. RTU has remote function, local function and self-checking and self-adjusting function. It is far away from the dispatch center and is connected to the dispatch center computer through a channel; its local function refers to the ability of the RTU to monitor and control the network locally through itself or connected display and recording equipment; the RTU program self-recovery Capability refers to the ability of the RTU to resume normal operation by itself when the program "fly" is affected by some interference. The PLC has only local functions.

Changsha Zhongke Zhilian Technology Co., Ltd. is mainly engaged in the research and development, production and sales of 4G industrial routers, 5G industrial routers, industrial switches, DTU, RTU, LoRa gateways and smart device products. With the corporate positioning of "humanization, specialization, and technology", we continue to attract professionals with high quality and high education to join us; with the rapid development of the market economy, our company has achieved nearly 100 companies in foreign markets. Including the United States, Germany, Russia, Egypt, India, Thailand, Singapore, Vietnam, India, Australia and more than 50 countries. And we will always maintain our development momentum, continue to expand domestic and foreign markets, and become bigger and stronger. All colleagues of Changsha Zhongke Zhilian Technology Co., Ltd. have always adhered to the premise of technological development and innovation, and customer service as the basis, and constantly improved the construction of the company's soft and hard facilities.